Re: [linux-dvb] [PATCH] Userspace tuner

Markus Rechberger
2007-09-14T16:09:42Z

On 9/14/07, Manu Abraham <abraham.manu@gmail.com> wrote:
> Joerg Roedel wrote:
> > On Fri, Sep 14, 2007 at 11:57:59AM +0400, Manu Abraham wrote:
> >>>>> What do you think about IOMMU?
> >>>>>
> >>>>>
> >>>> Just because AMD or INTEL want to invent some whizzy new technology it
> >>>> doesn't say anything about the TV card development and retail business.
> >>>> Intel and AMD have teams of Linux engineers helping operating system
> >>>> developers bring their ideas and technologies to new platforms. That's
> a
> >>>> million miles away from any of the TV board vendors I know of, who have
> >>>> little or NO fulltime linux developers and consider the < 5% market
> >>>> fringe at best.
> >>>>
> >>> it helps to virtualize devices and introduces newer features for that.
> >>> Some interesting projects could be derrived out of that, there are
> >>> quite a few interesting papers floating around how drivers could be
> >>> handled in future.
> >>>
> >> IOMMU can be considered similar to the AGP GART, which is similar,
> >> remapping the Addresses, as far as i understand.
> >
> > Common new IOMMUs have only very few in common with the AGP GART. In
> > fact, with current modern IOMMU hardware it will be possible to
> > implement secure userspace device drivers that are even able to do DMA.
> > This is not possible with the GART.
> >
> >> Though you get a physical to virtual translation, what about interrupts,
> >
> > Modern IOMMUs are able to remap interrupts. This will solve the problem
> > with PCI interrupt sharing.
>
> What CPU's are we talking about ?
>

upcoming x86-64 processors from the AMD side. I'm not into what Intel
is doing in that area at the moment.

Markus